( ical Bioscience Division of LBNL. It in...)Light-sensitive photoswitches could restore sight to those with macular degeneration

The researchers demonstrated in 2004 that they could turn cultured nerve cells on and off with this optical switch. Since then, with UC Berkeley Professor of Vision Science and Optometry John Flannery, they've injected photoswitches into the eyes of rats that have a disease that kills their rods and cones, and have restored some light sensitivity to the remaining retinal cells.

Isacoff, Kramer, Flannery and Trauner have now joined forces with 9 other researchers from UC Berkeley and LBNL, as well as from Stanford University, Scripps Institution of Oceanography and the California Institute of Technology, to perfect this fundamental development and bring it closer to medical application. Their group, centered around the optical control of biological function, will develop viruses that can carry the photoswitches into the correct cells, new types of photoswitches based on other chemical structures, and strategies for achieving the desired control of cell processes.

"The research will focus on one major application: restoring the response to light in the eyes of people who have lost their photoreceptor cells, in particular, the rods and cones in the most sensitive part of the retina," Isacoff said. "We plan to develop the tools to create a new layer of optically active cells for the retina."

Loss of photoreceptors - the light detectors in the retina - is the major cause of blindness in the United States. One in four people over age 65 suffers vision loss as a result of this condition, the most common diagnosis being macular degeneration.

The chemistry at the core of the photoswitch is a molecule - an azobenzene compound - that changes its shape when illuminated by light of different colors. Kramer, Trauner and
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Source:University of California - Berkeley